In electronic mails at a mobile terminal, there exist a number of unsolicited bulk e-mails (Spam mail) intentionally continuously sent to a receiver, although the receiver does not want to receive. In view of the characteristics of the mobile terminal, a data transfer rate is low, and communication cost is higher, and thus, the receiver's time-based and cost-based inconveniences become high. As one of countermeasures for rejecting such an unsolicited bulk e-mail, a white list having listed up transmitters for permitting mail reception every receiver's mobile unit is provided at a server, and it has been practiced to distribute an electronic mail to the receiver's mobile unit by using this list.
In this method, a white list is provided at an e-mail server in association with each receiver's mobile unit; a transmission mail address allowed for reception of an e-mail specified by the receiver's mobile unit is inputted via a communication line; and then, the inputted address is registered in the white list that corresponds to the receiver's mobile unit. The mail server compares a transmission source mail address of an e-mail transmitted to the receiver's mobile unit with a reception allowable mail address received in the white list that corresponds to the receiver's mobile unit. As a result of the comparison, only the e-mail whose transmission source mail address has been judged as being registered in the white list is distributed to the receiver's mobile unit. As a result, the receiver's mobile unit can receive only the e-mail desired by a user of this receiver's mobile unit. In this manner, it becomes possible to reject reception of an unsolicited bulk e-mail that the receiver does not want to receive.
The technical documents relating to the unsolicited bulk e-mails exist as follows.
Patent document 1: JP 2001-298522 A
Patent document 2: JP 2003-46576 A
Patent document 3: JP 2003-150512 A